/*
 * Copyright (C) 2005-2011 MaNGOS <http://www.getmangos.com/>
 *
 * Copyright (C) 2008-2011 Trinity <http://www.trinitycore.org/>
 *
 * Copyright (C) 2010-2011 ProjectSkyfire <http://www.projectskyfire.org/>
 * 
 * Copyright (C) 2011 ArkCORE <http://www.arkania.net/>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include "gamePCH.h"
#include "Common.h"
#include "ByteBuffer.h"
#include "WorldPacket.h"
#include "UpdateData.h"
#include "Log.h"
#include "Opcodes.h"
#include "World.h"
#include "zlib.h"

UpdateData::UpdateData() :
		m_map(0), m_blockCount(0) {
}

void UpdateData::AddOutOfRangeGUID(std::set<uint64>& guids) {
	m_outOfRangeGUIDs.insert(guids.begin(), guids.end());
}

void UpdateData::AddOutOfRangeGUID(const uint64 &guid) {
	m_outOfRangeGUIDs.insert(guid);
}

void UpdateData::AddUpdateBlock(const ByteBuffer &block) {
	m_data.append(block);
	++m_blockCount;
}

void UpdateData::Compress(void* dst, uint32 *dst_size, void* src,
		int src_size) {
	z_stream c_stream;

	c_stream.zalloc = (alloc_func) 0;
	c_stream.zfree = (free_func) 0;
	c_stream.opaque = (voidpf) 0;

	// default Z_BEST_SPEED (1)
	int z_res = deflateInit(&c_stream, sWorld->getIntConfig(CONFIG_COMPRESSION));
	if (z_res != Z_OK) {
		sLog->outError(
				"Can't compress update packet (zlib: deflateInit) Error code: %i (%s)",
				z_res, zError(z_res));
		*dst_size = 0;
		return;
	}

	c_stream.next_out = (Bytef*) dst;
	c_stream.avail_out = *dst_size;
	c_stream.next_in = (Bytef*) src;
	c_stream.avail_in = (uInt) src_size;

	z_res = deflate(&c_stream, Z_NO_FLUSH);
	if (z_res != Z_OK) {
		sLog->outError(
				"Can't compress update packet (zlib: deflate) Error code: %i (%s)",
				z_res, zError(z_res));
		*dst_size = 0;
		return;
	}

	if (c_stream.avail_in != 0) {
		sLog->outError(
				"Can't compress update packet (zlib: deflate not greedy)");
		*dst_size = 0;
		return;
	}

	z_res = deflate(&c_stream, Z_FINISH);
	if (z_res != Z_STREAM_END) {
		sLog->outError(
				"Can't compress update packet (zlib: deflate should report Z_STREAM_END instead %i (%s)",
				z_res, zError(z_res));
		*dst_size = 0;
		return;
	}

	z_res = deflateEnd(&c_stream);
	if (z_res != Z_OK) {
		sLog->outError(
				"Can't compress update packet (zlib: deflateEnd) Error code: %i (%s)",
				z_res, zError(z_res));
		*dst_size = 0;
		return;
	}

	*dst_size = c_stream.total_out;
}

bool UpdateData::BuildPacket(WorldPacket *packet) {
	ASSERT(packet->empty()); // shouldn't happen

	ByteBuffer buf(
			2 + 4
					+ (m_outOfRangeGUIDs.empty() ?
							0 : 1 + 4 + 9 * m_outOfRangeGUIDs.size())
					+ m_data.wpos());

	buf << uint16(m_map);
	buf << uint32(!m_outOfRangeGUIDs.empty() ? m_blockCount + 1 : m_blockCount);

	if (!m_outOfRangeGUIDs.empty()) {
		buf << uint8(UPDATETYPE_OUT_OF_RANGE_OBJECTS);
		buf << uint32(m_outOfRangeGUIDs.size());

		for (std::set<uint64>::const_iterator i = m_outOfRangeGUIDs.begin();
				i != m_outOfRangeGUIDs.end(); ++i) {
			buf.appendPackGUID(*i);
		}
	}

	buf.append(m_data);

	size_t pSize = buf.wpos(); // use real used data size

	if (pSize > 100) // compress large packets
			{
		uint32 destsize = compressBound(pSize);
		packet->resize(destsize + sizeof(uint32));

		packet->put<uint32>(0, pSize);
		Compress(const_cast<uint8*>(packet->contents()) + sizeof(uint32),
				&destsize, (void*) buf.contents(), pSize);
		if (destsize == 0)
			return false;

		packet->resize(destsize + sizeof(uint32));
		packet->SetOpcode(SMSG_COMPRESSED_UPDATE_OBJECT);
	} else // send small packets without compression
	{
		packet->append(buf);
		packet->SetOpcode(SMSG_UPDATE_OBJECT);
	}

	return true;
}

void UpdateData::Clear() {
	m_data.clear();
	m_outOfRangeGUIDs.clear();
	m_blockCount = 0;
	m_map = 0;
}
